1. Field of the Invention
The present invention generally relates to a motor driven air compressor and hydraulic pump module for vehicles, and more particularly, a mechanism that makes it possible to operate an air compressor and a hydraulic pump with one motor under each operational condition.
2. Description of Related Art
FIG. 1 shows a motor driven air compressor and a hydraulic pump module which are configured to operate a hydraulic pump 502 for a power steering system and an air compressor 504 that compresses air, using one motor 500.
As shown, the hydraulic pump 502 is directly connected to the rotary shaft of motor 500 and the air compressor 504 is connected to motor 500 by a clutch 506, a pulley 508, and a belt 510.
As such, torque from the motor 500 is transmitted to the air compressor 504 through the belt 510, by connection/disconnection of the clutch 506.
Therefore, the air compressor 504 functions by cutting the power from the motor 500 to the belt 510 by disconnecting the clutch 506 when operation of the air compressor 504 is not needed, and operating or connecting the clutch 506 to transmit the power from the motor 500 to the belt 510 when operation of the air compressor 504 is required.
However, in the structure described above, the gear ratio of the clutch 506 and pulley 508 is fixed to a predetermined level, such that the rotational speed of air compressor 504 cannot be adjusted, but rather only the on/off states can be provided.
Further, according to this structure, since transmission of torque to the air compressor 504 is controlled by the clutch 506, the air compressor 504 is thus suddenly connected/disconnected to/from the motor 500 which rotates at high speed by load. As such, both the motor 500 and air compressor 504 are likely to be damaged by sudden changes in torque.
Further, when the torque of the air compressor 504 is suddenly changed by the clutch 506, as described above, water may be produced in the pipe connected to the air compressor 504 by a sudden change in pressure.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.